Tail rose and propeller struck the ground during control demonstration.

Attributes
ACN	91874
Time
Date	198808
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : gmu
State Reference	SC
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : cvg
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	ground other : taxi
Flight Plan	None
Person 1
Affiliation	Other
Function	instruction : instructor
Qualification	pilot : cfi pilot : commercial pilot : instrument
Experience	flight time last 90 days : 98 flight time total : 1563 flight time type : 50
ASRS Report	91874
Person 2
Affiliation	Other
Function	instruction : trainee
Qualification	pilot : student
Events
Anomaly	other anomaly
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Consequence	other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was giving dual instruction. After completing the runup at the end of runway 36 at gmu, I decided to demonstrate to the student the importance of maintaining aft pressure on the yoke to prevent the tail from rising. I added power and applied forward pressure on the yoke. When the tail started to rise I applied aft pressure on the yoke. The tail continued to rise until the propeller contacted with the ground. The WX at gmu was 7000 scattered 3 mi in haze and the wind was 040 degrees at 10 KTS. I believe a gust of wind got the tail rising fast enough that reversed control input was not enough to stop it. Problem was misjudgment on my part to attempt the demonstration. In doing it I contradicted what I was teaching. In the future I will only explain (not demonstrate) this principle and use this experience as an example.

Original NASA ASRS Text

Title: TAIL ROSE AND PROPELLER STRUCK THE GND DURING CONTROL DEMONSTRATION.

Narrative: I WAS GIVING DUAL INSTRUCTION. AFTER COMPLETING THE RUNUP AT THE END OF RWY 36 AT GMU, I DECIDED TO DEMONSTRATE TO THE STUDENT THE IMPORTANCE OF MAINTAINING AFT PRESSURE ON THE YOKE TO PREVENT THE TAIL FROM RISING. I ADDED PWR AND APPLIED FORWARD PRESSURE ON THE YOKE. WHEN THE TAIL STARTED TO RISE I APPLIED AFT PRESSURE ON THE YOKE. THE TAIL CONTINUED TO RISE UNTIL THE PROP CONTACTED WITH THE GND. THE WX AT GMU WAS 7000 SCATTERED 3 MI IN HAZE AND THE WIND WAS 040 DEGS AT 10 KTS. I BELIEVE A GUST OF WIND GOT THE TAIL RISING FAST ENOUGH THAT REVERSED CTL INPUT WAS NOT ENOUGH TO STOP IT. PROB WAS MISJUDGMENT ON MY PART TO ATTEMPT THE DEMONSTRATION. IN DOING IT I CONTRADICTED WHAT I WAS TEACHING. IN THE FUTURE I WILL ONLY EXPLAIN (NOT DEMONSTRATE) THIS PRINCIPLE AND USE THIS EXPERIENCE AS AN EXAMPLE.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.